From c434e0a5a52f108860209fc58c91927ab32a8c45 Mon Sep 17 00:00:00 2001
From: Carl Worth <cworth@cworth.org>
Date: Fri, 3 Aug 2007 22:23:33 -0700
Subject: [PATCH] Generalize histogram printing to accept a predicate function

---
 mnemon.c | 67 +++++++++++++++++++++++++++++++++++++++-----------------
 1 file changed, 47 insertions(+), 20 deletions(-)

diff --git a/mnemon.c b/mnemon.c
index 52a77d0..446d449 100644
--- a/mnemon.c
+++ b/mnemon.c
@@ -323,6 +323,27 @@ bin_item_index (bin_t	*bin,
     assert (0);
 }
 
+typedef int (item_match_predicate_t) (void *closure, item_t *item);
+
+/* Return the number of items in the bin from the given category (or
+ * from all categories if category == NULL) */
+static int
+bin_num_items_matching (bin_t			*bin,
+			item_match_predicate_t	*predicate,
+			void			*closure)
+{
+    int i, num_items = 0;
+
+    if (predicate == NULL)
+	return bin->num_items;
+
+    for (i = 0; i < bin->num_items; i++)
+	if ((predicate) (closure, bin->items[i]))
+	    num_items++;
+
+    return num_items;
+}
+
 static void
 mnemon_init (mnemon_t *mnemon)
 {
@@ -760,23 +781,20 @@ mnemon_item_category (mnemon_t	*mnemon,
     assert (0);
 }
 
-/* Return the number of items in the bin from the given category (or
- * from all categories if category == NULL) */
-static int
-mnemon_bin_num_items_in_category (mnemon_t	*mnemon,
-				  bin_t    	*bin,
-				  category_t	*category)
+typedef struct _item_in_category_closure
 {
-    int i, num_items = 0;
-
-    if (category == NULL)
-	return bin->num_items;
+    mnemon_t *mnemon;
+    category_t *category;
+} item_in_category_closure_t;
 
-    for (i = 0; i < bin->num_items; i++)
-	if (mnemon_item_category (mnemon, bin->items[i]) == category)
-	    num_items++;
+static int
+mnemon_item_in_category (void *closure, item_t *item)
+{
+    item_in_category_closure_t *iicc = closure;
+    mnemon_t *mnemon = iicc->mnemon;
+    category_t *category = iicc->category;
 
-    return num_items;
+    return (mnemon_item_category (mnemon, item) == category);
 }
 
 static void
@@ -861,17 +879,26 @@ mnemon_print_histogram (mnemon_t    *mnemon,
     category_t *category = NULL;
     bin_t *bin;
     int num_items;
+    item_match_predicate_t *predicate = NULL;
+    void *closure = NULL;
+    item_in_category_closure_t item_in_category;
 
     if (mnemon->num_bins == 0)
 	return;
 
-    if (category_name)
+    if (category_name) {
 	category = mnemon_get_category_if_exists (mnemon, category_name);
+	if (category) {
+	    predicate = mnemon_item_in_category;
+	    item_in_category.mnemon = mnemon;
+	    item_in_category.category = category;
+	    closure = &item_in_category;
+	}
+    }
 
     for (i = 0; i < mnemon->num_bins; i++) {
-	num_items = mnemon_bin_num_items_in_category (mnemon,
-						      &mnemon->bins[i],
-						      category);
+	num_items = bin_num_items_matching (&mnemon->bins[i],
+					    predicate, closure);
 	if (i == 0 || num_items > max)
 	    max = num_items;
     }
@@ -881,8 +908,8 @@ mnemon_print_histogram (mnemon_t    *mnemon,
 	if (i != 0)
 	    while (bin->score - last_score > 1)
 		printf (HISTOGRAM_ROW_FORMAT "\n", ++last_score, 0);
-	num_items = mnemon_bin_num_items_in_category (mnemon,
-						      bin, category);
+	num_items = bin_num_items_matching (bin,
+					    predicate, closure);
 	printf (HISTOGRAM_ROW_FORMAT " ", bin->score, num_items);
 	print_histogram_bar (num_items, max);
 	last_score = bin->score;
-- 
2.43.0